Figure 6. The role of the muscarinic receptors in CST’s protective effect on apoptosis.

(a) Western blot analysis of effect of non-selective M receptor antagonist atropine, selective M1 receptor antagonist pirenzepine and selective M2 receptor antagonist AF-DX116 on ER-stress markers expression and phosphorylation of ERK1/2 and Akt and (b) M2 receptor-specific blocking confirmed with methoctramine and himbacine. Quantitative analysis of protein expression was shown in the bottom of figure. *P < 0.05 vs A/R treatment; ^#P < 0.01 vs A/R + CP group. Six independent experiments were performed for above studies. In neonatal rat cardiomyocytes, we measured the apoptosis markers-PARP and caspase-3 cleavage, ER-stress markers-Grp78 and Chop expression, ERK1/2 and Akt phosphorylation; and the role of M2 receptor using selective M2 receptor antagonists(c). Relative protein expression was performed (d). Three independent experiments were performed for it.